Apron drier



Aug. 6, 1929. L BUCK 1,723,917

' APRON DRIER Filed Feb. l, 1926 '7 Sheets-Sheet 2 :ui "l f5) nu L. BUCKAPRON DRI ER Aug. 6, 1929.

Filed Feb. 1', 1926 7 Smeets-Sheet 3 Aug. 6, 1929. L.. BUCK 1,723,917

APRON DRIER Filed Feb. l, 1926 Sheets-Sheet 4 Aug. 6, 1929.

L. BUCK APRON DRIER Filed Feb. l, 192@ 7' Sheets-Sheet 5 L. BUCK1,723,917

APRoN DRIER y Filed Feb. l, 1926 7 Sheets-Sheet' ,6

M 1%, mw y. 1 l ,l ,uw m m m m m m m m m m uw m m mmmmm m mw/ mw, e EIuw ww l m m m w m m m m m m m m m Aug. 6, 1929.

Aug. 6, 1929.

l.. BUCK 1,723,917

APRON DRIER I Filed Feb. l, 1926 7 Sheets-Sheet 7 Sb I :i K Lfii: wenimm Patented Aug.r6,vl929. Y I l. l, Y, l' ,i UNITED :STATES PATENTOFFICE..

l l i i LUCIEN BUCK, or JAMATCA PLAIN, MASSACHUSETTS, 'ASSIGNOR' To B.F. STURTEVANT COMPANY, oF HYDE PARK, MASSACHUSETTS, A CORPORATION FMASSACHU- SETTS. y l

ArRoN DRIER.

Application filed February 1, 1926. Serial No. 85,102. t i

'111e present invention relates to apparatus shoddy rubber, although itis' to be underfor (l1-ying material and more particularly stood thatthe illustrated drier may be used to that type of drying apparatusknownas for drying other materials either of a apron driers in which.the material 1s dried fibrous or solid character, and that the inwhileit is being carried along on a convention may beembodied in other formsand 60 3.01. 0,. WML y I constructions. In these drawings, Figure 1Heretofore driers of this type Vhave been shows the drier in frontelevation; Fig. 2 is used with light-weight, loose packing ma anenlarged, longitudinal vertical section of terial over or through whichthe drying air the right-hand end of the apparatus showil 1o has beencirculated atlow pressure. lVhere in Fig. 1; Fig. 3 is`an enlarged fronteleva- 65 relatively heavy, close-packing material has' tion of thereceiving portion l'of the drier, been sought to be dried on this typeof apshovving the spreading mechanism; Fig. 4 is paratus, diflicult-yhas been experienced not an end vierv of the same, partly in Vertical,only in properly supporting the heavy transverse section; Fig. 5 is avertical,

Weight of the material but in forcing the transverse section through theapparatus', 70 drying air through the same to remove the Y* showing thetop and bottom portions of oneI Vdesired amount of moisture. As a:.result it of the traveling conveyors and the several has been thegeneral practice' to dry such air ducts for the lsupply and return ofthe heavy. close-packing materials in small lots' drying air land forthe discharge of the same on shelves or trays where they stand exposedintovthe atmosphere; Fig. 6 is abottomplan 75, for-substantial periodsottime to the drying vieu', shoiving the perforated construction air.Such a process is necessarily slovv and4 of the conveyor and theScrapers for removexpensive. Moreover, where a `plural1ty of ing thesiftings from the top of the hot air aprons was employed, these werecommonly boxes;` Fig. 7 is a top plan View at the end 25 located inasingle chamber so that the mateof one of the hot air boxes, showing theper- 30 rial on the several aprons was all subjected.v Vforatedconstruction of the -top of the air 'to the same circulating flow ofair. The boxes and the serewonveyor for"dischargproper controlling. ofthe temperature, `hulng laterally the fsiftings delivered by the midity,and velocity of the air for the dlttcl'- Scrapers: Fig. 8 is a vertical,longitudinal 3o ent aprons, according to the character of the sectionshowing the method of mounting the 35 material, and the stage or degreeof dryness scraperspn the conveyor; and Fig: 9 is a attained, `wasimpossible. Furthermore, rear elevation of the apparatus,"showing the i'where the air was compelled to pass prodriving mechanism for theconveyors.

gressively Ythrough first one apron after an- The illustrated driercomprises primarily` other and the'material carried thereby, the, aserles of superposed',underlapping, con? 90 cumulative resistance wassuch that the cirtinuously operating aprons or conveyors. culation otthe ldrying air was so greatly- The material is delivered upon one endof retarded that the proper drying of the Inathe uppermost conveyor andat the other terial it attained at all, was secured only by; end thereofis vdischarged by gravity upon long continued treatment. v the lnext.lower gonveyortraveling in the op- 95 Itvisthe object ofthe presentinvention'to posite directio ,ffrom 'which it is in turn` produce adrier ofthe apron type 1n u'hlch discharged upon another oppositelytravelall classes of material may be dried to a'ny ing conveyor, and soon, the material dropdesired degree, automatically and continuping fromone convevor to another and passbusty, 1ivitli a minimum of time andexpense, ing back and forth, first in one direct-ion and 100 r and underproperly controlled conditions as then in the other, until finally it isdisfl to temperature, humidity andvelocity of the charged from thelowermost conveyor. drying air. f The drying of the material isy aecom-'lo the above ends the present invention plishedy by means of currentsof hotair deconsists in the drier hereafter described .andliveredlthrough air boxes underlyin the up- 105y more particularlydefinedin the claims. per section nof eah conveyor an having Theaccompanying drawingsV illustrate 'their top surfaces perforated todischarge `what is novv considered the preferred form the `heated airthrough. lThe conveyors or ot' the invention as embodied in a dryingap-` aprons are also perforated, and suitable parparatus particularlydesigned for drying titions and shields are provided so that air thepredetermined conveyors and through next lower a ron.

f able indicatin and humidity.

A11 of the apparatus except the receiving the material carried thereby.

In order to insure an even distribution of Vmaterial and an even depththereof over the conveyor or apron, a spreading or raking device hasbeen provided at the receiving end of the apparatus which stirs or'rakes ,the material transversely on the upper or )receiving apron, aleveling gage limiting the depth ofthe material on the apron as itpasses into the drier.

Means have also been provided at this portion of the apparatus forcollectinr andcar- ,rying away any. liquid or material which may dropthrough the conveyor or apron adjacent to its receiving end.

The apparatus also includes means for removing'from the to s of the airboxes such material as may si t through the perfora-5 tions in theconveyors 'during the drying operation, these means comprising Scrapersupon the bottom surfaces of the aprons or conveyors/which scrape thesiftings aloiig the top of theair boxes to their endsvwhere suchmaterial falls into a transverse trough in which a screw conveyor isoperating to discharge-th siftings laterally from the :Lp-s paratus,whence they are returned onto the Fans and' eating units are provided:to-

. ether with suitable conduits for suppl v'ng eat-ed air Ato the severalairboxes, an returning the same for reheating or discharg- )in into the'atmosphere dalnpers being suppliigd for controllin the flow of air andsuitan controlling devices for regulating the temperature indicating aiend of thetopiconveyor and the discharge end df the bottom conveyor isenclosed Vby insulated walls in which removable closuresA are providedfor the purpose of access to the interior of ,the drier.

' Referring now to the drawings, the `drierA thereimillustratedcomprises six superposed conveyors or aprons, forming-an apparatus ofsuch height that it is y located on two floors ofa factory. As showninFig. 1, the two upper conveyors, together with the fans and yheaternlits, are located onthe upper. floor 1 1, while the remainin fourconveyors are located directly beneat on the lower floor 12.AJ The upperconveyor 14 rec'eivs the moist material `at the left-hand end, as`

- viewedin Fig; 1 it being discharged from any suitable source of supplyinto a ho per 15 and thence on to the upper section o the conveyor. Asthe material moves to the right it comes beneath the spreadingmechanism, to be described more in detail later, where it is spread ordistributed uniformly `and evenly over the conveyor or apron.

A trough`or tank 19 beneath the conveyor lat this point serves to catchany free liquid or material which may drop through the apron.

After passing the spreader and the trough which are unenclosed, thematerial on the conveyor passesinto the -closed-in portion the drierpass over the air box 21 which extends beneath the upper section oftheconveyor substantiall from one end yto the other. The top o this air boxis provided with numerous 'small circularI holes 22 as shown in Fig. 7,through which the heated air is discharged directly against the bottomof theconveyor or apron. This also is perforated, being formedwith alarge number of rectangular openings 23-as shown in F ig. 6, formingawmesh or rid construction to permit the air/filo pass trough and overthe material supported on the conveyor.

During the traveling of the material across the drier or conveyor 14, asubstantial amount of the moistureis removed, and when the materialreaches the right-hand end of the machine it falls by gravity from theupper conveyor 14 to t esecond conveyor 25, being guided thereon by theinclined guides or chute 26. This second conveyor 25 travels .in the oposite 'direction to the top conveyor 14 an terial back-:to the left asviewed in Figs. 1 and 2, passing over an air box 27- similar to 21.

When the material on this second conveyor reaches the left-hand side ofthe drier, it is discharged into a hoplper 29 and chute 30 extendingdown throng the floory 11, and is delivered on to the third conveyor 32trav- 4liyng to the right. It is again subjected to ing action from vtheair in box 34 and is then delivered successively to conveyors 35, 36 and37, each having its own air box 3 8, 39 and 4U respectively. The.lefthand end ofthe conveyor 3'( extends beyond the enclosed portions ofthe apparatus, as

shown in Fig. 1, and from the end of this whereby the sections arepivoted or hingedVV upon a section of tubing or piping 43 whlch in turnis loosely mounted upon a shaft 45.

This shaft-comprises a tube or pipe 46 in carries the ma-v 1 y theVangle mounted upon the uprights 54 of the main structure` and upon thehorizontal brackets 55 secured to such uprights. W'ooden strips 56 areprovided at the out-er edges of the metal track 52 to serve as guides orabutments for the ends of the shafts 47 and I thereby prevent lateraldisplacement of the apron and wearing of the apron chain.

These tracks extend, nearly to the endsof the apron or conveyor andsupport both the top and bottom sections. VThe receiving end ofthe trackis bent downwardly as shown at 58, (see'Fig. 2),`to insure the properand easy engagement of the rollers therewith.

The conveyors or-aprons are supported at t each end upon sprockets ofwhich one is power driven and the other an idler. Thus in `the topmostconveyor the left-hand sprocket 61 turns idly Wit-h the-movement of theapron. These sprockets are provided with teeth 62 .which enter betweenthe side bars or ,links 5() an engage with i the rollers 49. Y'

Means are4 provided as l.is usual .in sprocket and chain constructionlfor varying the distance between the sprockets, such means comprising,as shownA in Fig. 3. a

`movable bearing block 64 adjustable in the slotted guide 65 by meansothe adjusting screw 66.`

The spreading orgdistributing mechanism for spreading the materialuniforml over the first conveyor at its receiving end),I comprises twosets of vertical rods or teeth which are moved transversely to thefeedtof the material by eccentric driving 'mechanism, the "two seriesbeing reciprocated simultaneously in op osite directions. This mechanismis best s ownin Figs. 3 and 4, the rods 68 being fixed in thebars 69which are mounted to slide in the guides or bearings 70. The bars arereciprocated by means of the eccentrics 71 set 180 apart on the shaft72, the eccentric straps 73, and the arms 74 pivotally connected to thevertical arms 75 fixed upon the bars 69,4 As thef shaft 72 is rotatedthrough the gear 76, the

'bars 69 are reciprocated in opposite direc-- tions and the pins orteeth- 68 act lto spread the material uniformly over the apron, at

the same time breaking up any large lumps that may be present. A f

The leveler gage or gate 20 consists of a vertical section mounted uponthe vertical support or channel 54 by bolt and slot-conH nection tolprovide for vertieal adjustment' for the purpose of regulating the depthof material on the conveyor:

The air boxes for delivering the drying Nof' a workman.

air imlnediately beneath each perforated apron or conveyor extendbeneath the upper section thereof nearly to its ends. As

shown in Figs. 1 and 2 these boxes are -dccplest at themiddle of thedrier where they Hreceive their supply of heated air, the depthprogressively diminishing towards each end.

In older to compel the heated air discharged .from these air boxes topass through the conveyor and the material carried thereon, means areprovided for preventing the escape of air downwardly on each side of thean' box or upwardly around the edges ofv the conveyor. The downwardlower or inner edges of these shields are so close to the upper surfaceof the conveyor if not actually in contact therewith that anysubstantial escape of'air around the sides and over the top of theconveyor is prevent ed. -These shields also serve as guards to prevent`the material carried by the conveyor from falling oli' the sidesthereof.

yThese partitions 77' `and the airboxes34, 38,

39 and 40 it will`be noted, divide the drier into a plurality of dryingchambers, cach having its supply of heated air and a single loaded apronpassing therethrough.

In order'to give access to the interior of the air 'boxes itocca-sion'should arise either for the purpose of inspection, cleaning,or repair, the removable closures 88 have been provided, each openinginto a box and being of suflicient size to permit the passa-ge Heatedair is supplied to the boxes from the fans and heaters, all of which forconvenience are mounted on the second floor' of the installation. sshownin'the drawings, three of these heat-ing and fan units are provided,each unit supplying air to twojof the boxes. Thls unit 82 suppliesheated air to the vertical supplyconduit 83 which communicates with thetwo upper boxes y2l and 27 at their middle. Unit 84 delivers air throughits supply conduit 85'to box '34 and .the box` immediately beneath it,while unit.

86 supplies air through its conduit- 87 to the two lowermost-boxes.

Brovision is made for the recirculation ot the .heated air, or of suchportion thereof as is desired, by means of return conduits cx tendingfroml above each conveyor or apron to its proper heater and fan unit.These return conduits are best shown in Figs. 1

'151. these conduits.

' Witha down-turned .edge or lip 107) and '5. For example, returnconduits 89 and 90 return the air to the heater and fan unit 84, whileconduits 91 and. 92 return the air to unit 86. These lconduits, as bestshown in Fig. 5, are provided at their ends with short branch conduits94 which pass through the side wall ofthe drier and terminate in thedownwardly open ends 95. A damper 96 controls the return flow of airthrough `The discharge of air fromabove the conveyors .or aprons intothe atmosphere is controlled by lmeans ofr'danipers 98 lin the dischargeconduits 99, extending through the wall of the drier. By properregulation of these dampers 96 and 98 the operator can recirculate yanddischarge the desired amounts of heated air. A supply' of fresh air isprovided through the inlet 100 in the Y suction conduit adjacent thefan, the closure 101 for which may be opened by the operator to thedesiredA extent. Suitable indieating devices are provided to show thetemperature and humidity of the drying air, such as wet and dry bulb`thermometers,

indicated at 102.

- lThe devices for removing from the top` of the air boxes the llinermaterial whic sifts down through the perforated conveyor comprisesscraper blades mounted upon the lbottom faces' of the conveyor,whichscrape hor push these siftings along the top of the A q lair box to theend thereof, where\ they f all f into a transverse trough or channel inwhich a screw conveyor is rotating and carries the siftings to theoutside of the drier. These scrapers are best shown in Figs. 6 and 8 andcomprise a pair of scraper blades 103 of libre or other suitablematerial secured to 40 the under side of the conveyor in a somewhatoblique or angular arrangement, with ltheir adjacent ends fastenedtogether and slightly behind, in the direction of travel, their distantends. These blades are free to move up and down to adjust themselves forslight variations in the level of the'top of the air box. The method ofmounting these` scraper blades-is Vshown in Fig. 8 where arf angle' iron104 is riveted to the bottomv face of the convefyor and is provided withvertical slots 105 pass'through the metal the fibre Scrapers 103. A

These Scrapers .are spaced at intervals on or the bolts which wear strip106 and L each conveyor, and the end of the box toward which theconveyor moves is 'royiddd vide. an eas the scraper lades with the-topthe-feed screw- 111 which is continuously ro'- t0 Plo. and gradualengagement of of the box. 60 The( opposite endof they box i. e. the endtated through the sprocket 112 by mechanism which is driven from theadjacent sprocket shaft. The siftings which are scraped along the top ofthe box by the scraper blades,fall down into the trough 109, alongwhicht-hey are carried by the feed screw until they drop into the chute113 outside the drier. This chute extends down- Wardly and then inwardlythrough the wall of the drier and delivers the siftings onto theconveyor or apron next below.l

The driving mechanism for the several sprockets of the conveyors isshown in Fig. 9, which is a rear elevation of the drier. The power shaft115 is driven from any -suitable source of power and through the pinion116 drives the gears 117 and V118 in opposite directions. Sprocketchains 119 and 120 drive the counter shafts 121 and 122 respectively.Counter shaft 121 drives the sprocket shafts 123 and 124 and theintermediate shaft 125 from which is driven the sprocket shaft 126.'Counter shaft 122 drives sprocket shaft 127 and intermediate shafts 128and 129 from which sprocket ,shafts 130 and 131 respectively are driven.

The drier is enclosed in.an insulated casing made in the form of anelsand bolted or otherwise secured to t e framework of the machine. Thesepanels, as shown in Fig. 5comprise a thick sheet of insulating materialprotected on both sides by a thin metal cover.

The operation ofthe drier is as follows. The shoddy rubber or othermaterial to be dried is delivered into the hopper 15 from which itpasses to the upper section of tho top conveyor. As the material passesfrom beneath the hopper it is distributed or spread by rmeans ofthespreading mechanism, the larger pieces or lumps being broken up. Atthe same time any excess -of liquid and some of the smaller particles of`material drop through the apron and fall into the tank 19. .l

The material on the conveyor then passes beneath" the leveler and entersthe closed drier and passes over the perforated upper surface of the airbox from which heated air at the desired temperature and humidity isflowing. under the action of the heater and fan.' There bein .no escapesave throughl the apron and the material, the heated air passesthroughthem, removing moisture from the material in vits passage. Such'portion of this air will be permitted Jto escape into the atmospherethrou h box 99 as may be r uired to maintain the proper humidity, t eremainder being returned to the heater where it is again heated withadditional fresh air and then returned to the air box. i

Meanwhile' the material has been assing throu h the drier `and when itreaciies the right and end, as the conveyor turns downwardly around ytheidle sprocket, is diss charged upon` the next lower conveyor by which itis carried. back through the drier in the opposite direction and againsubjected to the action ofthe drying air. Any material which siftsthrough the-openings will be scraped along the top of thebox and finallydischarged into the trough and thence bythe screw carried to the Chutelo 113 by which it is returned to the next apron below. f 1 l 'Thematerial passes back and forth through the'drier falling from oneyconveyor t onto the one next below, and in suchl trans- ]5 fer beingthoroughly mixed and turned, with the result that all surfaces andallparticles of the material are exposed to the drying air. Finally thematerial is carried out o the y closed drier by the lowermost conveyorand 2o discharged in a uniformly and thoroughly dried condition. 4

By the above described construction both light and heavy material ma bedriedcon! tinuously, automatically an expeditiously. VThe use of theperforated metallic conveyor and the tubular supporting members en.

ables heavy weights of`material 'to ,be carried, and by compelling theair to pass through such conveyor and tle material,relativelyclose-packing material may be thor-f oughly and uniformlyAdried. By the con- I tnuous` removal of any lsiftings which may passVthrough the perforated conveyor, cloggin or interference with the airsupply is avoided and the drier may operate on long AstretchesL withoutthe necessity of being periodically shut down` for cleaning.,

Since mechanism is provided which not only spreads and distributes thematerial evenly over the perforated conveyor but i. which serves also tobreak up and reduce any large' lumps, the drier is enabled to vhandlethe materlal more elliciently bothas to time r uired and degree ofdryness secured. y

he division of the device into separate chambers eachl havin its ownsupply of heated air and its sing e'loaded apron avoids thehighAcumul'ative resistances ofj prior driers -where the air (passedthrough one apronafter another successively.,y Furthermore, the'temperature, humidity and velocity ofthe drying air applied to thematerial at different stages of the d ryin may be independently variedand contro ed to suit the varied conditions `at such stages, therebyincreasing ,the speedof drying, desired rssy uality and rendering thevapparatus indepen ent of atmospheric conditions, such as excessivehumidity in the summer time.

While the present invfention has been shown and describedin connectionwitha drier designed primarily fr'handlinga particular material, it isto be understood thatl it is not limited thereto, but may be used withother materials and the form and ar msuring the top and a bottom havinga perforate middle f portion and imperforate marginal portions, 75

a perforate .traveling conveyor traveling through the chamber above theperforate A bottom, shields extending from Athe sidesfof the chamberclose to the traveling conveyor whereby the air from the perforatebottom is compelled to pass through the perforate conveyor and thematerial carried thereby, and means for delivering heated air throughthe perforate bottom.

2. In an apparatus `of the character described, the combination with achamber closed at its sides, of a rail on each side of the chamber, aperforate traveling con'- veyor, means for supporting the same comprising rolls at each side thereof traveling on said rails, an air box'beneaththe conveyor and having a perforate top to discharge air againstthe conveyor, means extending fromv the sides of the chamber in closeproximity to the top of the conveyor to prevent the escape ofair aroundthe edges oft-he conveyor, and means for delivering air to the boxes. i

3. In an apparatus of thev cha/racter de. scribed the combination with atraveling perforate conveyor, of an air box beneath the. same,A atransverse trough at the end of the air box, a screw feed inA saidtrough, and a scraper attached to the bottom lof the conveyor to scrapeany, material which-passes. throughthe perforate conveyor from the topof the, air box finto said trough.` 4. In an apparatus of the characterdescribed the combination with a plurality of superposed perforatetraveling conveyors, air boxes beneathy the same, means for 'removingfrom the top of the air boxes any material which passes through theconveyors and dea vices for delivering such material onto a lowerconveyor.

5,. In an apparatus of the character dei scribed the combination with' atraveling conveyor, of an air box located beneath the conveyor, and ascraper secured to the bottom of the conveyor to scrape the materialfrom thetop of the Aair box, said scraper comprising a blade arrangedtransversely` of the con- .veyor, and means for supporting the bladehaving provision for vertlcal movement of the same relatively to theconveyor.

6.'In an apparatus ofthe character de# scribed .the combination with aconveyor, of under side thereof,

a'scr per mounted on the `said scraper comprising two blades obliquelarranged end-to-end with their adjacent endg through the conveyor,

lair beneath the conveyor, tached to the under surface o f the conveyor.

behind, in respect tothe direction of move-a ment, their distant ends,and means for securing the blades to the conveyor having provision forvertical movement of the blades c relatively to the conveyor.

7. In an apparatus of the character described the combination with amain cham ber, of .a plurality of superposed, looped,

traveling conveyors, the top and )bottom conveyors extending to pointsoutside said lchamber for the receipt and the discharge respectively ofthe material to be treated, partitions in said chamber to form separateddrying .chambers through which the conveyors carry the material, meansfor ,heating the air, conduits for delivering the same to each dryingchamber, a return conduit from each chamber to' the heating means, anexhaust conduit from each chamber tothe at- `mosphere, and means underthe control of the operator for controlling the lowpof air Athrough thereturn yandthe exhaust conduits of an drying chamber independently of anof t e other chambers.-

-8. n an apparatus ofthe character de.

for scraping the vmaterial from said surfaces topermit acess of the airto the conveyor.

9..'In an apparatus of the character described the combination withl achamber having a perforate conveyor spaced abovefthe bottomof thechamber, means for supplying air to thechamber, a scraper mounted uponthe bottom side ofy the conveyor and'engaging the-bottom ofthe chamber,means adjacent the end of the kchamber to discharge the scraped materialvlaterally of the conveyor.

10. In anap aratus of the character described the com ination with aplurality of dryingichambers of a plurality of su'perposed underlappingpertorate traveling conveyors passing through the drying chambers, anair box beneath each conveyorhaving a perforate top toV permit thedischarge of heated air through the perforate conveyor, each air boxhaving an imperforate bottom, shields extending from the top of cach airbox to the sides of the chamber, the top 'of the drving chamber for theconveyor immediately below lcomprising said imperforate bottom and saidshields, and means for heated air to the boxes. i-

11. In an apparatus rof the character described the combination with achamber closed at its sides of a rail on each side of the chamber, aperforate traveling conveyor, means for supporting the conveyorcomprising rolls at each side thereof traveling on the rails, an air boxofless width `than the conveyor arranged beneath the conveyor andadapted to discharge air upwardly against the conveyor, means fordelivering air to the air box, and shields extending' from the sides ofthe chamber in close proximity to Athe top of the conveyor lto preventescape of air around the edges of the conveyor.

In 'testimony whereof I have signed my name to this specification.`

LUCIEN BUCK.

supplying

